Portfolio
Doctor.
Paste what you own and get a second opinion in seconds. The Doctor runs every check this site has on each holding, then looks at the portfolio as a whole: where it is concentrated, which positions deserve a closer look, how much your holdings move together, and how your mix would have fared in four past crashes.
Private by design. Your holdings are checked in this browser and saved only in its local storage. Nothing is uploaded or sent to us.
How each finding is decided
| Finding | Clean | Watch | Flag |
|---|---|---|---|
| Largest position | under 20% | 20% to 35% | over 35% |
| Number of holdings | 5 or more | 3 or 4 | fewer than 3 |
| Biggest sector | under 35% | 35% to 50% | over 50% |
| Profit quality | no Weak stocks, under 40% Mixed | any Weak, or 40%+ Mixed | 10%+ of the weight is Weak |
| Balance-sheet safety | no distress, under 15% grey | 15%+ in the grey zone | any holding in the distress zone |
| Valuation (weighted margin of safety) | 0% or more | 0% to −30% | below −30% |
| Overlap (weighted average correlation) | under 0.40 | 0.40 to 0.60 | over 0.60 |
| Dividend safety | no traps | – | any holding failing 3+ of the 6 dividend checks |
- Watch-only notes: a holding that looks cheap but fails most fundamental filters (value trap), two or more Munger inversion flags, more than 5% of the float sold short, or ranking below the sector median on most measures.
- Valuation: each stock's margin of safety is capped at ±100% before it is averaged by weight, so one stock trading at ten times its cash-flow value can't decide the verdict.
- Weights: shares are priced at the latest price in the weekly data. A holding with no amount gets the average of the others, and the page says so. With no amounts at all, everything is equal-weighted.
- Every holding is scored with the same functions as its stock card (margin of safety, Altman Z″, the five earnings-quality checks, Munger's inversion check, peer ranks), so the Doctor never disagrees with a card. Click any row to open it.
- Overlap: the weighted average pairwise correlation of daily returns over about two years, and the portfolio's volatility against the weighted average stock's.
- Crashes: your holdings in today's proportions, bought in the S&P 500's peak week and held to its bottom, from weekly closes (price only). Holdings not yet trading are left out and named.
What this can't do
- Only the stocks tracked here. About 500 US-listed stocks. Funds, ETFs, bonds, crypto and non-US stocks are skipped and named, so a portfolio that is mostly index funds gets little out of this.
- It doesn't know you. Your goals, taxes, time horizon, other accounts and what you paid are all invisible to it. The rules are generic screens, not advice.
- The valuation read is neutral. It uses one cash-flow DCF baseline (8% growth, 10% discount) for every stock, so a growth-heavy portfolio will often look expensive. Treat it as “how much of the future are you paying for”.
- Correlation looks backward. Holdings that moved independently for two years can fall together in a real crisis; that is exactly what the crash replay is for.
- A flag is a question, not a verdict. Open the stock card to see what is behind it.
On Oct 23, 2026, the Portfolio Doctor's built-in example, eight US stocks held in different amounts, gets 9 Clean and 15 Flag grades across its 40 position checks (value, safety, profit quality, the Munger check and peers). The largest holding is Palantir Technologies (PLTR) at 21% of the portfolio.
What the Doctor
found.
Ranked from most to least pressing. A cross is something to look at first, an exclamation mark a thing to keep an eye on, a tick means that part is in good shape. Names are buttons: click one to open its stock card.
Position by
position.
The same checks the stock card runs, side by side. Weight is how much of your portfolio each holding is. Click a row for the full stock card.
What you
actually own.
Where the money sits, how cash-backed the profits are, how sturdy the balance sheets are, and what you are paying for it all.
Biggest positions
Sectors
Do your holdings
move together?
Owning ten stocks that rise and fall in step is closer to owning one. This measures how closely your holdings' daily moves have tracked each other over about two years, weighted by how much you hold.
Waiting for the check-up…
How your mix
fared in a crash.
Your holdings in today's proportions, replayed through four S&P 500 crashes: split at the peak, held to the bottom. Bars run left for a loss and right for a gain, from the old peak. Price only, weekly closes, no rebalancing, fees or taxes.
Waiting for the check-up…
What does the Portfolio Doctor say about an example portfolio?
On Oct 23, 2026, the Portfolio Doctor's built-in example, eight US stocks held in different amounts, gets 9 Clean and 15 Flag grades across its 40 position checks (value, safety, profit quality, the Munger check and peers). The largest holding is Palantir Technologies (PLTR) at 21% of the portfolio. Paste your own holdings above to see yours; they stay in your browser.
| Holding | Weight | Value | Safety | Profit quality | Munger check | Vs. peers |
|---|---|---|---|---|---|---|
| PLTRPalantir Technologies Inc | 21% | Flag (−718%) | Clean (Safe) | Flag (Weak) | Flag (3 flags) | Clean (4 of 6) |
| AAPLApple Inc | 18% | Flag (−116%) | Watch (Grey) | Clean (Strong) | Flag (3 flags) | Flag (2 of 7) |
| MSFTMicrosoft Corp | 17% | Flag (−244%) | n/a | Clean (Strong) | Flag (2 flags) | Watch (3 of 7) |
| JNJJohnson & Johnson | 12% | Flag (−68%) | n/a | Clean (Strong) | Watch (1 flag) | Watch (3 of 7) |
| JPMJPMorgan Chase & Co | 9% | n/a | n/a | n/a | Clean (0 flags) | Watch (2 of 4) |
| NVDANVIDIA Corp | 8% | Flag (−147%) | Clean (Safe) | Flag (Weak) | Flag (2 flags) | Clean (5 of 7) |
| KOCoca-Cola Co | 8% | Flag (−65%) | Clean (Safe) | Watch (Mixed) | Watch (1 flag) | Watch (3 of 7) |
| XOMExxonmobil Holdings Corp | 7% | Flag (−40%) | n/a | Watch (Mixed) | Watch (1 flag) | Flag (2 of 7) |
Clean, Watch and Flag are the Doctor's own grades on this site's disclosed thresholds; a flag is a reason to look closer, not a reason to sell, and a clean result is not a reason to hold. The Doctor also checks how concentrated the mix is, how much the holdings move together and how the mix fared in four past crashes. The example is not a recommendation.
Holdings are a built-in example. Per-stock numbers come from the same data as each stock's own page, refreshed weekly. Educational content only, not investment advice.
Frequently asked questions
Is my portfolio uploaded anywhere?
No. The Doctor runs entirely in your browser. What you paste is saved only in your browser's local storage on your own device, and nothing is sent to a server.
What does the Portfolio Doctor check?
For each holding: value (margin of safety on the site's DCF), safety (Altman Z-Score), profit quality, the Munger inversion check and how it ranks against its sector peers. For the whole portfolio: concentration by position and sector, how much the holdings move together, and how the mix fared in past crashes.
What can I paste into it?
Tickers with an optional amount, as shares, dollars or percent, one per line or as a CSV, up to 40 holdings. Only the roughly 500 US stocks this site tracks are checked. Funds, ETFs and other tickers are listed as not understood instead of being silently dropped.
Does a clean result mean I should keep a stock?
No. A clean grade means a stock passed this site's generic, disclosed screens, not that it suits your goals, taxes or other assets. A flag is a reason to look closer, not a reason to sell.
Why does a holding show no data on some checks?
Banks, insurers, REITs and utilities are not valued with a free-cash-flow DCF, and some companies lack enough filings for profit quality or the balance-sheet score. They show n/a on those checks.
About this free portfolio check-up
Paste your holdings into the portfolio doctor for a free, private portfolio check-up: concentration risk, profit quality, financial safety, valuation, overlap between holdings and how your mix fared in past market crashes. It runs in your browser, so nothing you paste is uploaded. Compare ideas in the stock screener afterwards. Look up any holding's own page in the A to Z directory, and see the market backdrop on the crash indicator and the sector valuation map, which replays past crashes by sector.
Educational content only, not investment advice. The Portfolio Doctor applies generic, disclosed screens to the holdings you type in; it knows nothing about your goals, taxes or other assets, and a clean result is not a recommendation to hold, just as a flag is not a recommendation to sell. Always read a company's own filings before acting. See Editorial Standards and Disclosures for more, and the glossary for any term.